Solid Oxide Fuel
Cell Turbofan Engine
CFM56-7b
Engine
Neil Skilton (skiltn@uw.edu)
Stuart Greenwood (stujgree@uw.edu)
Sam Eads-Ford (samef@uw.edu)
Project Goal
To determine if large commercial aircra can be
powered by non-carbon emitting engines while still attaining
similar range and payload properties of existing commercial aircra
(targeted to 737 and A320 sized aircra).
Why?
Aircra account for 12 percent of all U.S. transportation and greenhouse
emissions and 3 percent of total U.S. GHG emissions. Given the increased
public awareness of the aviation sector’s current impact on global
greenhouse emissions, there is growing pressure to limit aviation
generated greenhouse emissions.
What We Did!
Our group looked at the high electric and thermal output of solid oxide
fuel cells (SOFC) and found that, with some adjustments to existing turbo
fan engines, a hybrid engine could be created that uses both combustion
and solid oxide fuel cells to provide carbon free propulsion for large
transport aircra.
Solid Oxide Fuel
Cell Turbofan Engine
Aer building an annular combustion chamber (seen above), we performed many computational fluid dynamics
runs in order to validate the CFD model. In an attempt to accurately model the mixing within the combustion chamber, swirlers were
added to the metering panel in the forward part of the combustion chamber. To get better heat transfer, we turned to using simple
heating fins. All the faces were defined to give out a set amount of power and placed just in front of the inlets. To see if the heating ele-
ment was ruining the flow, we used a sphere for the heating element as it would disturb the flow the least. This did dramatically de-
crease the surface area interacting with the flow, but we were hoping the lack of interference with the flow would allow at least a por-
tion of the coreflow to heat up to the right temperature. This was all done in an attempt to model the heat transfer associated with
combustion because SolidWorks could not model combustion.
Our solid oxide fuel cell design will provide high energy output in
the form of both electrical and thermal energy. These cells are
expected to reach around 1100 degrees celsius, where this ther-
mal energy will be used to help maintain core flow. The electrical
energy from the cells will run to the high pressure compressor to
also help maintain core flow. This electric energy
will run to six 1.1 MW electric motors that will run
the compressor. Each number corresponds to a
location on the Brayton Cycle diagram.
Human Constraints
- Limited access to the fuel cell assembly for maintenance.
- Working with hydrogen/fuel cells requires special training and safety procedures.
- Building and reading a system to monitor every step and aspect of the hydrogen fuel/fuel cell. These
systems will be complex and require special training to monitor.
Technical Constraints
- Hydrogen fuel is lighter than regular JET-A fuel but has a larger volume and thus requires more storage.
High density solutions such as Cryogenic storage work well but is very expensive.
- The fabrication of a 3D printed SOFC is still being explored in the advancement of fuel cell production.
Having to use a traditional SOFC could result in not enough power (Thermal and Electric) and adding too
much weight.
- The infrastructure for production of Liquid Hydrogen needs to be developed to support aviation usage.
Testing
Power Cycle
Joshua Mundt (mundtj@uw.edu)
Caleb Taing (calebkt@uw.edu)
Group
Members
Dr. Yshiteru Itagaki
Dr. Dustin McLarty
Dr. Steven Collins
Dr. Subramanian Ramchandran
Those Who Have Helped
Dr. Pierre Mourad
Tim Skilton
Dr. Imen Hannachi
Teddy Johnson
How This Changes the World
What We Made
- The system is optimized by using a combination of SOFC and hydrogen combustion for
takeoff and climb with the combustion system reduced to essential pilot fuel nozzle for
cruise and decent while relying on the SOFC for the majority of the power.
- The power unit produces 6.33 MW of
electric power that runs through
cryogenically cooled electric motors.
The remaining waste thermal power is
captured by the low pressure turbine
and transferred to the low pressure sha.
You can see our Hydrogen Fuel System to
the right.
- The base Dual Annular Combustion Chamber (DAC on the le) had to
be customized to fit our Fuel Cell Stacks. The finished product can be
seen on the right.
- We then created a hybrid engine incorporating
both a combustion chamber and fuel cells
which provides adequate thrust throughout the
flight profile.
- Out of all the heavy modes of transport, aircra contribute the most to CO2 emissions,
as you can see below. Replacing all active 737 and A320 aircra with our custom engine
would save 51
million metric
tons of CO2 per
year, which is
the equivalent
of planting 58
million trees
per year.
-The 3D printed cell stack our
design is based off of has 1/10
the thickness of conventional
technology!
- Hydrogen fuel cells can be used for a wide range of applications such as generating
power for satellites and spaceships, to powering fuel cell vehicles like automobiles,
buses, or boats, and also generating primary or emergency backup power for buildings,
all while being carbon free. Solid Oxide Fuel Cells hold the greatest capability due to
their high electrical efficiency, high temperatures and low operating costs. This is the
first carbon free propulsion system for large transport aircra in the world!
References
- https://www.business-
wire.com/news/home/20150223005522/en/F-
CO-Power-Develops-Next-Generation-Solid-Oxide-Fuel
- https://www.bloomenergy.com/blog/every-
thing-you-need-know-about-solid-oxide-fuel-cells
- https://www.thermofisher.com/blog/materials/analyz-
ing-the-com-
position-of-a-solid-oxide-fuel-cell-during-thermal-cycling/
- http://www.supercoloring.com/coloring-pages/boeing-737
- https://petrolog.typepad.com/climate_change/2009/09/car-
bon-emissions-from-aircra-and-ships.html
Notice of Resitriction on Disclosure. This document may contain trade
secrets, confidential, proprietary, or priveleged information that is
exempt from public disclosure. Such information shall be used or
disclosed only for academic evaluation purposes.
- We took the total volume and target power needed
and compared those with the power output of the 3D
printed cells we are using. Then found the correct
volume needed to use the original fuel injector spaces
for 20 fuel cell stacks. We optimized the dimensions of
the stacks while expanding radially outward and elon-
gating the DAC. With
the help of heat fins
and strategic hole
patterns on the
metering panel directly
forward of the cells, we
achieved the correct thermal flow.